1. Technical Field
The present invention relates to a vehicle tire, particularly for motor vehicles.
2. Background Information
In particular, the present invention relates to a vehicle tire comprising an outer tread; two beads; two bead fillers; and two annular sidewall portions, each connecting a respective bead to the tread, and each reinforced internally by at least two first layers of reinforcing cords on opposite sides of the bead and extending substantially radially outwardly from the bead, to define a chamber housing the bead and respective filler.
The tires on a motor vehicle form part of a system for damping the vibration transmitted to the vehicle by contact with the road surface. Moreover, inside the tire, certain parts, such as the tread and sidewall portions, i.e. the lateral portions of the tire connecting the tread to the bead portions, define specific shock absorbers capable of absorbing relatively low-frequency vibrations. As regards the sidewall portions, an important point to bear in mind is that the rigidity of these portions affects, not only the ability of the tire to absorb varying, relatively low-frequency radial loads, but also the response of the tire to transverse loads. In other words, by varying the rigidity of the sidewall portions, it is possible to vary the cornering capability of the tire.
There are numerous prior art tires, such as shown in U.S. Pat. Nos. 3,994,329 and 4,287,924 in which the sidewalls are provided with rigid support members of a crescent or lenticular cross-section formed of various hardened rubber which will support the weight of the tire, enabling the tire to run under nearly normal conditions even with complete loss of the inflation air.
Although these safety tire constructions, referred to as "run-flat" tires, do provide rigidity to the sidewalls, the stiffened rubber sidewall inserts increase the weight of the tire.